UCLA's ST5 fluxgate magnetometer is the product of a long series of successful spaceflight magnetometers. The sensors are boom mounted and have no active components. Drive, sense and feedback signals travel along the boom cable between the sensors and the electronics board on the spacecraft. The electronics whose functional block diagram is shown below generates the fluxgate drive signal, detects the second harmonic of this signal, nulls the field surrounding the sensor, and provides a digital reading of the current needed to null each of the sensors. This signal is then sent to the telemetry system. There is no microprocessor in this simple design. The magnetometer has two commandable ranges, 64,000 and 1000 nT.
The fluxgate sensors in the UCLA magnetometer are manufactured using the
Drive and Sense Circuits
The proposed ST5 magnetometer uses the classic fluxgate circuit presented shown below. Sensor mass and power are kept low with a dual core series drive circuit. The dynamic range is changed from 64,000 nT to 1000 nT by altering the closed loop response from 64,000 nT range to 5000 nT, and then amplifying the signal to get to a 1000 nT range. This method keeps the noise low in both ranges. One gain change command line switches both elements.
ST5 Magnetometer Design Specifications
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For more information, contact Robert J. Strangeway, firstname.lastname@example.org.
Last updated June 11, 2001